1
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Chaparro-Pedraza PC. Differential Stage-Specific Mortality as a Mechanism for Diversification. Am Nat 2024; 204:E28-E41. [PMID: 39008841 DOI: 10.1086/730446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
AbstractIndividual variability in mortality is widespread in nature. The general rule is that larger organisms have a greater chance of survival than smaller conspecifics. There is growing evidence that differential mortality between developmental stages has important consequences for the ecology and evolution of populations and communities. However, we know little about how it can influence diversification. Using an eco-evolutionary model of diversification that considers individual variability in mortality, I show that commonly observed differences in mortality between juveniles and adults can facilitate adaptive diversification. In particular, diversification is expected to be less restricted when mortality is more biased toward juveniles. Additionally, I find stage-specific differences in metabolic cost and foraging capacity to further facilitate diversification when adults are slightly superior competitors, due to either a lower metabolic cost or a higher foraging capacity, than juveniles. This is because by altering the population composition, differential stage-specific mortality and competitive ability can modulate the strength of intraspecific competition, which in turn determines the outcome of diversification. These results demonstrate the strong influence that ecological differences between developmental stages have on diversification and highlight the need for integrating developmental processes into diversification theory.
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2
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Miloch D, Cecchetto NR, Lescano JN, Leynaud GC, Perotti MG. Is thermal sensitivity affected by predation risk? A case study in tadpoles from ephemeral environments. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:400-409. [PMID: 38356256 DOI: 10.1002/jez.2793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/29/2024] [Accepted: 02/01/2024] [Indexed: 02/16/2024]
Abstract
Changes in environmental temperature may induce variations in thermal tolerance and sensitivity in ectotherm organisms. These variations generate plastic responses that can be analyzed by examining their Thermal Performance Curves (TPCs). Additionally, some performance traits, like locomotion, could be affected by other factors such as biological interactions (e.g., predator-prey interaction). Here, we evaluate if the risk of predation modifies TPCs in Mendoza four-eyed frog (Pleurodema nebulosum, Burmeister, 1861) and Guayapa's four-eyed frog (Pleurodema guayapae, Barrio, 1964), two amphibian species that occur in ephemeral ponds in arid environments. We measured thermal tolerances and maximum swimming velocity at six different temperatures in tadpoles under three situations: control, exposure to predator chemical cues, and exposure to conspecific alarm cues. TPCs were fitted using General Additive Mixed Models. We found that curves of tadpoles at risk of predation differed from those of control mainly in thermal sensitivity parameters. Our work confirms the importance of biotic interactions have in thermal physiology.
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Affiliation(s)
- Daniela Miloch
- Facultad de Ciencias Exactas, Físicas, y Naturales, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto de Diversidad y Ecología Animal, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Nicolas R Cecchetto
- Instituto de Investigaciones en Biodiversidad y Medio Ambiente, Consejo Nacional de Investigaciones Científicas y Técnicas, Bariloche, Río Negro, Argentina
| | - Julián N Lescano
- Facultad de Ciencias Exactas, Físicas, y Naturales, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto de Diversidad y Ecología Animal, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Gerardo C Leynaud
- Facultad de Ciencias Exactas, Físicas, y Naturales, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto de Diversidad y Ecología Animal, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - María Gabriela Perotti
- Instituto de Investigaciones en Biodiversidad y Medio Ambiente, Consejo Nacional de Investigaciones Científicas y Técnicas, Bariloche, Río Negro, Argentina
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3
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Chen A, Deng H, Song X, Liu X, Chai L. Effects of Separate and Combined Exposure of Cadmium and Lead on the Endochondral Ossification in Bufo gargarizans. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:1228-1245. [PMID: 35040517 DOI: 10.1002/etc.5296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/12/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Cadmium (Cd) and lead (Pb) are ubiquitous in aquatic environments and most studies have examined the potential effects of Cd or Pb alone on aquatic organisms. In the present study, chronic effects of Cd and Pb, alone and in combination, on Bufo gargarizans were investigated by exposing embryos to these contaminants throughout metamorphosis. Significant reductions in body mass and snout-to-vent length were observed in B. gargarizans at Gosner stage 42 (Gs 42) and Gs 46 exposed to a Cd/Pb mixture. Single and combined exposure with Cd and Pb induced histological alterations of the thyroid gland characterized by reduced colloid area and thickness of epithelial cells. There was a significant decrease in the maximum jump distance of froglets exposed to Cd alone and the Cd/Pb mixture, and the jumping capacity showed a positive correlation with hind limb length and tibia/fibula. Moreover, single metals and their mixture induced reduction of endochondral bone formation in B. gargarizans. Transcriptomic and real-time quantitative polymerase chain reaction results showed that genes involved in skeletal ossification (TRα, TRβ, Dio2, Dio3, MMP9, MMP13, Runx1, Runx2, and Runx3) were transcriptionally dysregulated by Cd and Pb exposure alone or in combination. Our results suggested that despite the low concentration tested, the Cd/Pb mixture induced more severe impacts on B. gargarizans. In addition, the Cd/Pb mixture might reduce chances of survival for B. gargarizans froglets by decreasing size at metamorphosis, impaired skeletal ossification, and reduction in jumping ability, which might result from dysregulation of genes involved in thyroid hormone action and endochondral ossification. The findings obtained could add a new dimension to understanding of the mechanisms underpinning skeletal ossification response to heavy metals in amphibians. Environ Toxicol Chem 2022;41:1228-1245. © 2022 SETAC.
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Affiliation(s)
- Aixia Chen
- School of Water and Environment, Chang'an University, Xi'an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, China
| | - Hongzhang Deng
- School of Water and Environment, Chang'an University, Xi'an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, China
| | - Xiuling Song
- School of Water and Environment, Chang'an University, Xi'an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, China
| | - Xiaoli Liu
- School of Water and Environment, Chang'an University, Xi'an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, China
| | - Lihong Chai
- School of Water and Environment, Chang'an University, Xi'an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, China
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4
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D’Errico M, Kennedy C, Hale RE. Egg mass polymorphism in Ambystoma maculatum is not associated with larval performance or survival, or with cell density of the algal symbiont Oophila amblystomatis. Evol Ecol 2020. [DOI: 10.1007/s10682-020-10083-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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5
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McCann S, Crossland M, Shine R. Exposure of cane toad hatchlings to older conspecifics suppresses chemosensory food tracking behaviour and increases risk of predation post-exposure. PLoS One 2020; 15:e0233653. [PMID: 32469938 PMCID: PMC7259751 DOI: 10.1371/journal.pone.0233653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 05/09/2020] [Indexed: 12/03/2022] Open
Abstract
Attempts to control invasive species using species-specific pheromones need to incorporate an understanding of interactive effects among those pathways. The larvae of invasive cane toads (Rhinella marina) utilise chemical cues to repulse, attract or suppress conspecific larvae. We can exploit these effects to reduce toad abundance, but the effects of each cue may not be additive. That is, exposure to one type of cue may lessen the impact of exposure to another cue. To assess this possibility, we exposed toad larvae to combinations of cues. Tadpoles that had been exposed to the suppression cue during larval development exhibited no response to the attraction cue, resulting in lower capture rates in attractant-baited traps. Suppression, however, did not affect a tadpole’s response to the alarm cue, and exposure to the alarm cue during tadpole development did not affect response to the attraction cue. Tadpoles exposed to the suppression cue were smaller than control tadpoles at 10 days post-exposure, and consequently were more vulnerable to gape-limited invertebrate predators. Our results demonstrate that the responses by toad tadpoles to chemical cues interact in important ways, and are not simply additive when combined. Control efforts need to incorporate an understanding of such interactions if we are to most effectively use chemical-communication pathways to control invasive amphibians.
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Affiliation(s)
- Samantha McCann
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
- * E-mail:
| | - Michael Crossland
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Richard Shine
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
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6
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Chaparro‐Pedraza PC, de Roos AM. Density-dependent effects of mortality on the optimal body size to shift habitat: Why smaller is better despite increased mortality risk. Evolution 2020; 74:831-841. [PMID: 32189326 PMCID: PMC7317909 DOI: 10.1111/evo.13957] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 02/11/2020] [Accepted: 02/20/2020] [Indexed: 12/02/2022]
Abstract
Many animal species across different taxa change their habitat during their development. An ontogenetic habitat shift enables the development of early vulnerable-to-predation stages in a safe "nursery" habitat with reduced predation mortality, whereas less vulnerable stages can exploit a more risky, rich feeding habitat. Therefore, the timing of the habitat shift is crucial for individual fitness. We investigate the effect that size selectivity in mortality in the rich feeding habitat has on the optimal body size at which to shift between habitats using a population model that incorporates density dependence. We show that when mortality risk is more size dependent, it is optimal to switch to the risky habitat at a smaller rather than larger body size, despite that individuals can avoid mortality by staying longer in the nursery habitat and growing to safety in size. When size selectivity in mortality is high, large reproducing individuals are abundant and produce numerous offspring that strongly compete in the nursery habitat. A smaller body size at habitat shift is therefore favored because strong competition reduces growth potential. Our results reveal the interdependence among population structure, density dependence, and life history traits, and highlight the need for integrating ecological feedbacks in the study of life history evolution.
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Affiliation(s)
- P. Catalina Chaparro‐Pedraza
- Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdam1090 GEThe Netherlands
- Eawag—Swiss Federal Institute of Aquatic Science and TechnologyDübendorfSwitzerland
| | - André M. de Roos
- Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdam1090 GEThe Netherlands
- The Santa Fe InstituteSanta FeNMUSA
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7
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Zamora‐Camacho FJ, Aragón P. Failed predator attacks have detrimental effects on antipredatory capabilities through developmental plasticity inPelobates cultripestoads. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13308] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Pedro Aragón
- Museo Nacional de Ciencias Naturales (MNCN‐CSIC) Madrid Spain
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8
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Hloušková M, Balogová M, Kršáková V, Gvoždík L. No trade-offs in interspecific interference ability and predation susceptibility in newt larvae. Ecol Evol 2018; 8:9095-9104. [PMID: 30271569 PMCID: PMC6157682 DOI: 10.1002/ece3.4465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/21/2018] [Accepted: 07/24/2018] [Indexed: 11/09/2022] Open
Abstract
Coexistence of species with similar requirements is allowed, among others, through trade-offs between competitive ability and other ecological traits. Although interspecific competition is based on two mechanisms, exploitation of resources and physical interference, trade-off studies largely consider only species' ability to exploit resources. Using a mesocosm experiment, we examined the trade-off between interference competition ability and susceptibility to predation in larvae of two newt species, Ichthyosaura alpestris and Lissotriton vulgaris. In the presence of heterospecifics, L. vulgaris larvae slowed somatic growth and developmental rates, and experienced a higher frequency of injuries than in conspecific environments which suggests asymmetrical interspecific interference. During short-term predation trials, L. vulgaris larvae suffered higher mortality than I. alpestris. Larvae of the smaller species, L. vulgaris, had both lower interference and antipredator performance than the larger I. alpestris, which suggests a lack of trade-off between interference competition ability and predator susceptibility. We conclude that interference competition may produce a positive rather than negative relationship with predation susceptibility, which may contribute to the elimination of subordinate species from common habitats.
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Affiliation(s)
- Monika Hloušková
- Department of Botany and ZoologyMasaryk UniversityBrnoCzech Republic
| | - Monika Balogová
- Institute of Biology and EcologyFaculty of ScienceP.J. Šafárik UniversityKošiceSlovakia
| | - Veronika Kršáková
- Department of Botany and ZoologyMasaryk UniversityBrnoCzech Republic
| | - Lumír Gvoždík
- Institute of Vertebrate Biology of the Czech Academy of SciencesBrnoCzech Republic
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9
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Lindgren B, Orizaola G, Laurila A. Interacting effects of predation risk and resource level on escape speed of amphibian larvae along a latitudinal gradient. J Evol Biol 2018; 31:1216-1226. [PMID: 29802672 DOI: 10.1111/jeb.13298] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 04/27/2018] [Accepted: 05/08/2018] [Indexed: 12/01/2022]
Abstract
Fast-growing genotypes living in time-constrained environments are often more prone to predation, suggesting that growth-predation risk trade-offs are important factors maintaining variation in growth along climatic gradients. However, the mechanisms underlying how fast growth increases predation-mediated mortality are not well understood. Here, we investigated if slow-growing, low-latitude individuals have faster escape swimming speed than fast-growing high-latitude individuals using common frog (Rana temporaria) tadpoles from eight populations collected along a 1500 km latitudinal gradient. We measured escape speed in terms of burst and endurance speeds in tadpoles raised in the laboratory at two food levels and in the presence and absence of a predator (Aeshna dragonfly larvae). We did not find any latitudinal trend in escape speed performance. In low food treatments, burst speed was higher in tadpoles reared with predators but did not differ between high-food treatments. Endurance speed, on the contrary, was lower in high-food tadpoles reared with predators and did not differ between treatments at low food levels. Tadpoles reared with predators showed inducible morphology (increased relative body size and tail depth), which had positive effects on speed endurance at low but not at high food levels. Burst speed was positively affected by tail length and tail muscle size in the absence of predators. Our results suggest that escape speed does not trade-off with fast growth along the latitudinal gradient in R. temporaria tadpoles. Instead, escape speed is a plastic trait and strongly influenced by the interaction between resource level and predation risk.
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Affiliation(s)
- Beatrice Lindgren
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Germán Orizaola
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Anssi Laurila
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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10
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Deslauriers D, Svendsen JC, Genz J, Wall AJ, Baktoft H, Enders EC, Anderson WG. Environmental calcium and variation in yolk sac size influence swimming performance in larval lake sturgeon ( Acipenser fulvescens). ACTA ACUST UNITED AC 2018; 221:jeb.164533. [PMID: 29440358 DOI: 10.1242/jeb.164533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 02/03/2018] [Indexed: 12/31/2022]
Abstract
In many animal species, performance in the early life stages strongly affects recruitment to the adult population; however, factors that influence early life history stages are often the least understood. This is particularly relevant for lake sturgeon, Acipenser fulvescens, living in areas where environmental calcium concentrations are declining, partly due to anthropogenic activity. As calcium is important for muscle contraction and fatigue resistance, declining calcium levels could constrain swimming performance. Similarly, swimming performance could be influenced by variation in yolk sac volume, because the yolk sac is likely to affect drag forces during swimming. Testing swimming performance of larval A. fulvescens reared in four different calcium treatments spanning the range of 4-132 mg l-1 [Ca2+], this study found no treatment effects on the sprint swimming speed. A novel test of volitional swimming performance, however, revealed reduced swimming performance in the low calcium environment. Specifically, volitionally swimming larvae covered a shorter distance before swimming cessation in the low calcium environment compared with the other treatments. Moreover, sprint swimming speed in larvae with a large yolk sac was significantly slower than in larvae with a small yolk sac, regardless of body length variation. Thus, elevated maternal allocation (i.e. more yolk) was associated with reduced swimming performance. Data suggest that larvae in low calcium environments or with a large yolk sac exhibit reduced swimming performance and could be more susceptible to predation or premature downstream drift. Our study reveals how environmental factors and phenotypic variation influence locomotor performance in a larval fish.
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Affiliation(s)
- David Deslauriers
- University of Manitoba, Department of Biological Sciences, 369 Duff Roblin, 190 Dysart Road, Winnipeg, MB R3T 2N2, Canada.,Fisheries and Oceans Canada, Central & Arctic Region, Freshwater Institute, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada
| | - Jon C Svendsen
- Fisheries and Oceans Canada, Central & Arctic Region, Freshwater Institute, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada .,Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.,Technical University of Denmark, National Institute of Aquatic Resources (DTU-Aqua), Section for Ecosystem based Marine Management, Kemitorvet, Building 201, DK-2800 Kgs. Lyngby, Denmark
| | - Janet Genz
- University of Manitoba, Department of Biological Sciences, 369 Duff Roblin, 190 Dysart Road, Winnipeg, MB R3T 2N2, Canada.,University of West Georgia, Biology Department, 1601 Maple Street, Carrollton, GA 30118, USA
| | - Alex J Wall
- Fisheries and Oceans Canada, Central & Arctic Region, Freshwater Institute, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada
| | - Henrik Baktoft
- Technical University of Denmark, National Institute of Aquatic Resources, Section for Freshwater Fisheries and Ecology, Vejlsøvej 39, DK-8600 Silkeborg, Denmark
| | - Eva C Enders
- Fisheries and Oceans Canada, Central & Arctic Region, Freshwater Institute, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada
| | - W Gary Anderson
- University of Manitoba, Department of Biological Sciences, 369 Duff Roblin, 190 Dysart Road, Winnipeg, MB R3T 2N2, Canada
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11
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Buhaciuc E, Székely P, Băncilă R, Cogălniceanu D. Food availability influences postmetamorphic growth in two spadefoot toad species (genus Pelobates). AMPHIBIA-REPTILIA 2017. [DOI: 10.1163/15685381-00003082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Understanding how major life history traits such as body size and mass and growth change in response to resource availability is crucial in explaining life history trade-offs. We conducted a laboratory experiment with three (high, medium and low) feeding intensity treatments using metamorphs of two spadefoot toads species,Pelobates syriacusandP. fuscus, from syntopic populations. We tested how total food consumption, final body size and mass, body mass increase, body mass and length growth rates and growth efficiency are influenced by food availability. The responses to food availability differed significantly between the species with respect to the total food consumption, body mass increase, body mass growth rate and growth efficiency (i.e. the ratio between total amount of food consumed during the experiment divided by the increase in body mass).P. syriacusmetamorphs had higher growth rates and growth efficiency thanP. fuscusjuveniles. Also,P. syriacusjuveniles responded to differences in food level by increasing growth efficiency with decreasing food levels. OverallP. syriacusseems better adapted to shortages in food availability thanP. fuscus. Our results clearly indicate that the differences in body size between the two species originate between metamorphosis and sexual maturity.
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Affiliation(s)
- Elena Buhaciuc
- Ovidius University Constanţa, Faculty of Natural and Agricultural Sciences, 900470 Constanţa, Romania
| | - Paul Székely
- Ovidius University Constanţa, Faculty of Natural and Agricultural Sciences, 900470 Constanţa, Romania
| | - Raluca Băncilă
- Ovidius University Constanţa, Faculty of Natural and Agricultural Sciences, 900470 Constanţa, Romania
- “Emil Racoviţă” Institute of Speleology of Romanian Academy, 13 Septembrie Road, 050711 Bucharest, Romania
| | - Dan Cogălniceanu
- Ovidius University Constanţa, Faculty of Natural and Agricultural Sciences, 900470 Constanţa, Romania
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12
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Influence of temperature on female, embryonic and hatchling traits in syntopic newts, Ichthyosaura alpestris and Lissotriton vulgaris. J Therm Biol 2017; 63:24-30. [DOI: 10.1016/j.jtherbio.2016.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 10/25/2016] [Accepted: 10/25/2016] [Indexed: 01/19/2023]
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13
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Ingley SJ, Camarillo H, Willis H, Johnson JB. Repeated evolution of local adaptation in swimming performance: population-level trade-offs between burst and endurance swimming inBrachyrhaphisfreshwater fish. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12852] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Spencer J. Ingley
- Evolutionary Ecology Laboratories; Department of Biology; Brigham Young University; Provo UT 84602 USA
| | - Henry Camarillo
- Evolutionary Ecology Laboratories; Department of Biology; Brigham Young University; Provo UT 84602 USA
| | - Hannah Willis
- Evolutionary Ecology Laboratories; Department of Biology; Brigham Young University; Provo UT 84602 USA
| | - Jerald B. Johnson
- Evolutionary Ecology Laboratories; Department of Biology; Brigham Young University; Provo UT 84602 USA
- Monte L. Bean Life Science Museum; Brigham Young University; Provo UT 84602 USA
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14
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Dugas MB, McCormack L, Gadau A, Martin RA. Choosy Cannibals Preferentially Consume Siblings with Relatively Low Fitness Prospects. Am Nat 2016; 188:124-31. [PMID: 27322127 DOI: 10.1086/686729] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
When an individual can selfishly cannibalize a relative or altruistically set it free, the benefits of altruism will be positively associated with the relative's fitness prospects (the benefits it receives from altruism). We tested the prediction that altruism should be preferentially directed toward high-quality relatives using larvae of the New Mexican spadefoot toad (Spea multiplicata), a species in which tadpoles plastically express omnivore and carnivore ecomorphs. In a no-choice design, we presented carnivores with sibling or nonsibling omnivores varying in developmental stage, which is positively associated with survival in this toad's ephemeral larval environment. There was a significant interaction between relatedness and developmental stage on the probability of cannibalism: carnivores were overall more likely to cannibalize less developed omnivores, but this effect was exaggerated when the potential victim was a sibling. This evidence that altruists favor relatives with high fitness prospects highlights the numerous factors shaping altruism's payoffs.
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15
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Perotti MG, Pueta M, Jara FG, Úbeda CA, Moreno Azocar DL. Lack of functional link in the tadpole morphology induced by predators. Curr Zool 2016; 62:227-235. [PMID: 29491910 PMCID: PMC5804239 DOI: 10.1093/cz/zow014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/10/2015] [Indexed: 11/14/2022] Open
Abstract
Most studies of predator-induced plasticity have focused on documenting how prey species respond to predators by modifying phenotypic traits and how traits correlate with fitness. We have previously shown that Pleurodema thaul tadpoles exposed to the dragonfly Rhionaeschna variegata responded strongly by showing morphological changes, less activity, and better survival than non-exposed tadpoles. Here, we tested whether there is a functional link between morphological plasticity and increased survival in the presence of predators. Tadpoles that experienced predation risk were smaller, less developed, and much less active than tadpoles without this experience. Burst speed did not correlate significantly with morphological changes and predator-induced deeper tails did not act as a lure to divert predator strikes away from the head. Although we have previously found that tadpoles with predator-induced morphology survive better under a direct predator threat, our results on the functional link between morphology and fitness are not conclusive. Our results suggest that in P. thaul tadpoles (1) burst speed is not important to evade predators, (2) those exposed to predators reduce their activity, and (3) morphological changes do not divert predator attacks away from areas that compromise tadpole survivalEE. Our results show that morphological changes in P. thaul tadpoles do not explain burst speed or lure attraction, although there was a clear reduction of activity, which itself reduces predation. We propose that changes in tadpole activity could be further analyzed from another perspective, with morphological change as an indirect product of behavior mediated by physiological mechanisms.
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Affiliation(s)
- María Gabriela Perotti
- Laboratorio de Fotobiología, INIBIOMA, CONICET-Universidad Nacional del Comahue, Quintral 1250, Bariloche, Rio Negro, Argentina
| | - Mariana Pueta
- Laboratorio de Fotobiología, INIBIOMA, CONICET-Universidad Nacional del Comahue, Quintral 1250, Bariloche, Rio Negro, Argentina.,Departamento de Biología General. Universidad Nacional del Comahue, Quintral 1250, Bariloche, Rio Negro, Argentina, and
| | - Fabián Gastón Jara
- Laboratorio de Fotobiología, INIBIOMA, CONICET-Universidad Nacional del Comahue, Quintral 1250, Bariloche, Rio Negro, Argentina
| | - Carmen Adria Úbeda
- Departamento de Zoología, INIBIOMA, CONICET-Universidad Nacional del Comahue, Quintral 1250, 8400, Bariloche, Rio Negro, Argentina
| | - Debora Lina Moreno Azocar
- Laboratorio de Fotobiología, INIBIOMA, CONICET-Universidad Nacional del Comahue, Quintral 1250, Bariloche, Rio Negro, Argentina
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16
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Kearney BD, Byrne PG, Reina RD. Short- and long-term consequences of developmental saline stress: impacts on anuran respiration and behaviour. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150640. [PMID: 26998337 PMCID: PMC4785988 DOI: 10.1098/rsos.150640] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 01/28/2016] [Indexed: 06/05/2023]
Abstract
Secondary salinization has been identified as a major stressor to amphibians. Exposure to elevated salinity necessitates physiological adjustments and biochemical changes that may be energetically demanding. As such, exposure to non-lethal levels of salinity during development could potentially alter anuran metabolic rates and individual performance in both pre- and post-metamorphic life stages. We investigated the effects of non-lethal levels of salinity on metamorphic traits (time to reach metamorphosis and metamorphic mass), tadpole oxygen consumption, escape response behaviour (pre- and post-metamorphosis) and foraging ability post-metamorphosis in two native Australian frog species, the southern brown tree frog (Litoria ewingii) and the striped marsh frog (Limnodynastes peronii). We found that both Lit. ewingii and Lim. peronii exhibited differences in metamorphic traits in response to elevated salinity. Neither species showed significant change in oxygen consumption during development in response to salinity, relative to freshwater controls. Both species displayed impaired escape response behaviours in response to salinity during larval development, but flow-on effects to adult escape response behaviours and foraging performance were species-specific. Our results show that the influence of stressors during development can have consequences for anuran physiology and behaviour at multiple life stages, and emphasize the need for studies that examine the energetics of anuran responses in order to better understand the responses of biota to stressful environments.
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Affiliation(s)
- Brian D. Kearney
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Phillip G. Byrne
- The Institute for Conservation Biology and Environmental Management, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Richard D. Reina
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
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17
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Gvoždík L, Smolinský R. Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae. BMC Evol Biol 2015; 15:238. [PMID: 26525734 PMCID: PMC4630873 DOI: 10.1186/s12862-015-0522-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 10/28/2015] [Indexed: 11/10/2022] Open
Abstract
Background Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Results Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. Conclusions In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator–prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator–prey interactions and food web dynamics. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0522-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lumír Gvoždík
- Institute of Vertebrate Biology AS CR, Květná 8, CZ 60365, Brno, Czech Republic.
| | - Radovan Smolinský
- Institute of Vertebrate Biology AS CR, Květná 8, CZ 60365, Brno, Czech Republic.
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18
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Growth Inhibition of Tadpoles Exposed to Sertraline in the Presence of Conspecifics. J HERPETOL 2014. [DOI: 10.1670/13-058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Katzenberger M, Hammond J, Duarte H, Tejedo M, Calabuig C, Relyea RA. Swimming with predators and pesticides: how environmental stressors affect the thermal physiology of tadpoles. PLoS One 2014; 9:e98265. [PMID: 24869960 PMCID: PMC4037208 DOI: 10.1371/journal.pone.0098265] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 04/29/2014] [Indexed: 12/02/2022] Open
Abstract
To forecast biological responses to changing environments, we need to understand how a species's physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4°C higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5°C, while exposure to the herbicide marginally lowered Topt by 0.4°C. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5°C higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.
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Affiliation(s)
- Marco Katzenberger
- Department of Evolutionary Ecology, Doñana Biological Station - Spanish Council for Scientific Research, Sevilla, Spain
| | - John Hammond
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Helder Duarte
- Department of Evolutionary Ecology, Doñana Biological Station - Spanish Council for Scientific Research, Sevilla, Spain
| | - Miguel Tejedo
- Department of Evolutionary Ecology, Doñana Biological Station - Spanish Council for Scientific Research, Sevilla, Spain
| | - Cecilia Calabuig
- Department of Animal Sciences, Federal Rural University of the Semiarid Region, Mossoró, Rio Grande do Norte, Brazil
| | - Rick A. Relyea
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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20
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Wang S, Lillywhite HB, Tu MC. Locomotor performance of three sympatric species of sea kraits (Laticauda spp.) from Orchid Island, Taiwan. Zool Stud 2013. [DOI: 10.1186/1810-522x-52-43] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Assuming that locomotion has a strong influence on animals’ fitness, we hypothesized that better locomotor performance would be associated with the most frequently utilized habitat. Laticauda colubrina, Laticauda laticaudata, and Laticauda semifasciata have different amphibious habits and microhabitat preferences at Orchid Island, Taiwan. We investigated the morphology and locomotor performance of the three sympatric species of sea krait. The measurements of body size, tail area, and body shape were compared in our study. Data on crawling and swimming speeds were gathered to investigate locomotor performance in terrestrial and aquatic environments.
Results
We found significant differences in the locomotor performances among the three species. L. colubrina was the most terrestrial species in habits and sprinted significantly faster than the others during terrestrial locomotion. On the other hand, L. semifasciata was the most aquatic species, and it swam significantly faster than the other two species. These results are consistent with our hypothesis that sea kraits move well in their respective primary environments. With respect to the highly aquatic L. semifasciata, its laterally compressed body form, large body size, and large area of compressed tail are considered to be beneficial to swimming in an aquatic environment.
Conclusions
More data are required to understand the superior terrestrial locomotion of L. colubrina, but this species may benefit from its more-cylindrical body form compared to L. semifasciata and from its greater muscle mass compared to L. laticaudata. L. laticaudata was intermediate in habits but exhibited the poorest performance in both swimming and terrestrial locomotion. The reasons for this remain unclear.
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21
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Stewart KA, Lougheed SC. Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer. Ecol Evol 2013; 3:4621-30. [PMID: 24363891 PMCID: PMC3867898 DOI: 10.1002/ece3.851] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/14/2013] [Accepted: 09/17/2013] [Indexed: 12/01/2022] Open
Abstract
Phenotypically cryptic lineages appear common in nature, yet little is known about the mechanisms that initiate and/or maintain barriers to gene flow, or how secondary contact between them might influence evolutionary trajectories. The consequences of such contact between diverging lineages depend on hybrid fitness, highlighting the potential for postzygotic isolating barriers to play a role in the origins of biological species. Previous research shows that two cryptic, deeply diverged intraspecific mitochondrial lineages of a North American chorus frog, the spring peeper (Pseudacris crucifer), meet in secondary contact in Southwestern Ontario, Canada. Our study quantified hatching success, tadpole survival, size at metamorphosis, and development time for experimentally generated pure lineage and hybrid tadpoles. Results suggest that lineages differ in tadpole survival and that F1 hybrids may have equal fitness and higher than average mass at metamorphosis compared with pure parental crosses. These findings imply hybrid early life viability may not be the pivotal reproductive isolation barrier helping to maintain lineage boundaries. However, we observed instances of tadpole gigantism, failure to metamorphose, and bent tails in some tadpoles from hybrid families. We also speculate and provide some evidence that apparent advantages or similarities of hybrids compared with pure lineage tadpoles may disappear when tadpoles are raised with competitors of different genetic makeup. This pilot study implies that ecological context and consideration of extrinsic factors may be a key to revealing mechanisms causing negative hybrid fitness during early life stages, a provocative avenue for future investigations on barriers to gene flow among these intraspecific lineages.
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Affiliation(s)
- Kathryn A Stewart
- Department of Biology, Queen's University Kingston, Ontario, Canada, K7L 3N6
| | - Stephen C Lougheed
- Department of Biology, Queen's University Kingston, Ontario, Canada, K7L 3N6
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22
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Wilcox SC, Lappin AK. Burst-swimming performance predicts the outcome of cannibalistic interactions in green poison frog larvae (Dendrobates auratus). ACTA ACUST UNITED AC 2013; 319:495-504. [DOI: 10.1002/jez.1813] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/09/2013] [Accepted: 06/28/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Sean C. Wilcox
- Biological Sciences Department; California State Polytechnic University; Pomona; California
| | - A. Kristopher Lappin
- Biological Sciences Department; California State Polytechnic University; Pomona; California
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23
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Alton LA, Franklin CE. Do high temperatures enhance the negative effects of ultraviolet-B radiation in embryonic and larval amphibians? Biol Open 2012; 1:897-903. [PMID: 23213484 PMCID: PMC3507240 DOI: 10.1242/bio.2012950] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/29/2012] [Indexed: 11/23/2022] Open
Abstract
For the embryos and tadpoles of amphibian species, exposure to ultraviolet-B radiation (UVBR) can be lethal, or cause a variety of sublethal effects. Low temperatures enhance the detrimental effects of UVBR and this is most likely because the enzyme-mediated processes involved in the repair of UVBR-induced damage function less effectively at low temperatures. Whether these repair processes are also impaired, and thus the negative effects of UVBR similarly enhanced, at high temperatures is not known, but is an ecologically relevant question to ask given that organisms that inhabit environments where the temperature fluctuates widely on a daily timescale are likely to experience high doses of UVBR when temperatures are high. Here we examined the thermal-dependence of UVBR effects in the context of an ecologically-relevant fluctuating UVBR and temperature regime to test the hypothesis that exposure to peak UVBR levels while the temperature is high (35°C) is more detrimental to embryonic and larval Limnodynastes peronii than exposure to peak UVBR levels while the temperature is moderate (25°C). Embryos exposed to peak UVBR levels at 35°C hatched 10 h later than those exposed to peak UVBR levels at 25°C and, as tadpoles, were smaller and consequently swam more slowly but, in an environment with predators, exhibited no difference in survival time. There was also no effect of experimental treatment on the hatching success of embryos, nor on the post-hatch survival of tadpoles. These findings, therefore, are not sufficiently strong to support our hypothesis that high temperatures enhance the negative effects of UVBR in embryonic and larval amphibians.
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Affiliation(s)
- Lesley A Alton
- School of Biological Sciences, University of Queensland , Brisbane QLD 4072 , Australia
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24
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Taborsky B, Heino M, Dieckmann U. Size-dependent mortality and competition interactively shape community diversity. Evolution 2012; 66:3534-44. [PMID: 23106716 DOI: 10.1111/j.1558-5646.2012.01692.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Body size is recognized as a major factor in evolutionary processes mediating sympatric diversification and community structuring. Life-history types with distinct body sizes can result from two fundamental mechanisms, size-dependent competition and size-dependent mortality. While previous theoretical studies investigated these two processes in separation, the model analyzed here allows both selective forces to affect body-size evolution interactively. Here we show for the first time that in the presence of size-dependent competition, size-dependent mortality can give rise to multiple, coexisting size morphs representing the final outcomes of evolution. Moreover, our results demonstrate that interactions between size-dependent competition and mortality can create characteristic abrupt changes in size structure and nonmonotonic patterns of biological diversity along continuous and monotonic environmental gradients. We find that the two selective forces differentially affect the body-size ratios of coexisting morphs: size-dependent competition results in small and relatively constant ratios, whereas size-dependent mortality can open niches for morphs that greatly differ in body size. We show that these differential effects result in characteristic distributions of size ratios across communities, which we suggest can help detect the concurrent action and relative influence of size-dependent competition and mortality in nature.
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Affiliation(s)
- Barbara Taborsky
- Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50A, CH-3032 Hinterkappelen, Switzerland.
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25
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Pfennig KS, Allenby A, Martin RA, Monroy A, Jones CD. A suite of molecular markers for identifying species, detecting introgression and describing population structure in spadefoot toads (Spea spp.). Mol Ecol Resour 2012; 12:909-17. [PMID: 22564443 DOI: 10.1111/j.1755-0998.2012.03150.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two congeneric species of spadefoot toad, Spea multiplicata and Spea bombifrons, have been the focus of hybridization studies since the 1970s. Because complex hybrids are not readily distinguished phenotypically, genetic markers are needed to identify introgressed individuals. We therefore developed a set of molecular markers (amplified fragment length polymorphism, polymerase chain reaction-restriction fragment length polymorphism and single nucleotide polymorphism) for identifying pure-species, F1 hybrids and more complex introgressed types. To do so, we tested a series of markers across both species and known hybrids using populations in both allopatry and sympatry. We retained those markers that differentiated the two pure-species and also consistently identified known species hybrids. These markers are well suited for identifying hybrids between these species. Moreover, those markers that show variation within each species can be used in conjunction with existing molecular markers in studies of population structure and gene flow.
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Affiliation(s)
- Karin S Pfennig
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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26
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Abstract
Animal aggregations are widespread in nature and can exhibit complex emergent properties not found at an individual level. We investigate one such example here, collective vortex formation by congeneric spadefoot toad tadpoles: Spea bombifrons and S. multiplicata. Tadpoles of these species develop into either an omnivorous or a carnivorous (cannibalistic) morph depending on diet. Previous studies show S. multiplicata are more likely to develop into omnivores and feed on suspended organic matter in the water body. The omnivorous morph is frequently social, forming aggregates that move and forage together, and form vortices in which they adopt a distinctive slowly-rotating circular formation. This behaviour has been speculated to act as a means to agitate the substratum in ponds and thus could be a collective foraging strategy. Here we perform a quantitative investigation of the behaviour of tadpoles within aggregates. We found that only S. multiplicata groups exhibited vortex formation, suggesting that social interactions differ between species. The probability of collectively forming a vortex, in response to introduced food particles, increased for higher tadpole densities and when tadpoles were hungry. Individuals inside a vortex moved faster and exhibited higher (by approximately 27%) tailbeat frequencies than those outside the vortex, thus incurring a personal energetic cost. The resulting environmental modification, however, suggests vortex behaviour may be an adaptation to actively create, and exploit, a resource patch within the environment.
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27
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28
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Castellanos I, Barbosa P, Zuria I, Tammaru T, Christman MC. Contact with caterpillar hairs triggers predator-specific defensive responses. Behav Ecol 2011. [DOI: 10.1093/beheco/arr085] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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29
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Luttbeg B, Sih A. Risk, resources and state-dependent adaptive behavioural syndromes. Philos Trans R Soc Lond B Biol Sci 2011; 365:3977-90. [PMID: 21078650 DOI: 10.1098/rstb.2010.0207] [Citation(s) in RCA: 241] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many animals exhibit behavioural syndromes-consistent individual differences in behaviour across two or more contexts or situations. Here, we present adaptive, state-dependent mathematical models for analysing issues about behavioural syndromes. We find that asset protection (where individuals with more 'assets' tend be more cautious) and starvation avoidance, two state-dependent mechanisms, can explain short-term behavioural consistency, but not long-term stable behavioural types (BTs). These negative-feedback mechanisms tend to produce convergence in state and behaviour over time. In contrast, a positive-feedback mechanism, state-dependent safety (where individuals with higher energy reserves, size, condition or vigour are better at coping with predators), can explain stable differences in personality over the long term. The relative importance of negative- and positive-feedback mechanisms in governing behavioural consistency depends on environmental conditions (predation risk and resource availability). Behavioural syndromes emerge more readily in conditions of intermediate ecological favourability (e.g. medium risk and medium resources, or high risk and resources, or low risk and resources). Under these conditions, individuals with higher initial state maintain a tendency to be bolder than individuals that start with low initial state; i.e. later BT is determined by state during an early 'developmental window'. In contrast, when conditions are highly favourable (low risk, high resources) or highly unfavourable (high risk, low resources), individuals converge to be all relatively bold or all relatively cautious, respectively. In those circumstances, initial differences in BT are not maintained over the long term, and there is no early developmental window where initial state governs later BT. The exact range of ecological conditions favouring behavioural syndromes depends also on the strength of state-dependent safety.
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Affiliation(s)
- Barney Luttbeg
- Department of Environmental Science and Policy, University of California at Davis, Davis, CA 95616, USA
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30
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Foster HR, Burton GA, Basu N, Werner EE. Chronic exposure to fluoxetine (Prozac) causes developmental delays in Rana pipiens larvae. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2010; 29:2845-2850. [PMID: 20836066 DOI: 10.1002/etc.345] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 06/14/2010] [Accepted: 08/11/2010] [Indexed: 05/29/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are among the many pharmaceuticals detected in aquatic ecosystems. Although the acute effects of SSRIs on select organisms have been reported, little is understood about the chronic effects of these drugs on amphibians, which are particularly sensitive to environmental pollutants. Serotonin plays important roles in many physiological functions, including a wide array of developmental processes. Exposure to SSRIs during development may cause developmental complications in a variety of organisms, but little is known about the degree of exposure necessary to cause deleterious effects. Here, we sought to gain a better understanding of the effects of SSRIs on amphibian development by use of a combined laboratory and outdoor mesocosm study. Tadpoles in a laboratory setting were exposed to a low (0.029 µg/L) and a high (0.29 µg/L) concentration of the common SSRI fluoxetine from stages 21 and 22 through completion of metamorphosis. Tadpoles in outdoor mesocosms were exposed to fluoxetine concentrations ranging from 0.1 to 0.3 µg/L. Exposed tadpoles in the laboratory showed delayed development compared with controls when stage was assessed throughout the experiment. Control tadpoles also gained weight faster than treatment tadpoles, which may be explained by reduced food intake. Mesocosm tadpoles exhibited similar trends, but no significant differences were detected. These results indicate that ecologically relevant levels of fluoxetine may cause developmental delays in amphibians.
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Affiliation(s)
- Hannah R Foster
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109, USA.
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31
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Arendt J. Morphological correlates of sprint swimming speed in five species of spadefoot toad tadpoles: Comparison of morphometric methods. J Morphol 2010; 271:1044-52. [DOI: 10.1002/jmor.10851] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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You can’t run but you can hide: refuge use in frog tadpoles elicits density-dependent predation by dragonfly larvae. Oecologia 2010; 163:395-404. [DOI: 10.1007/s00442-010-1568-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 01/13/2010] [Indexed: 11/26/2022]
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33
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Fight versus flight: the interaction of temperature and body size determines antipredator behaviour in tegu lizards. Anim Behav 2010. [DOI: 10.1016/j.anbehav.2009.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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